Troubleshooting:Old Dlls

The Error

When you build from source, then update the source, rebuild and try to run, you get strange runtime exceptions, usually along the lines of

 APPLICATION EXCEPTION DETECTED: System.UnhandledExceptionEventArgs
 Exception: System.MissingMethodException

The Problem

When you build the source, it's 'compiled' into runnable files called 'dlls' or Dynamic Link Libraries. These have the extension .dll and are added to your local installation, and are not governed by source control. When we change where these dlls are created, the 'old' ones, from previous builds, will still be there. This will cause the program to try and load these old dlls, with unexpected results.

The Solution

Usually, any of these remedies should fix the problem:

• Remove all OpenSim.*.dll (only files that starts with "OpenSim." and ends in ".dll", like "OpenSim.Framework.dll") from your installation directory, then rebuild and run.
• Do a 'nant clean' if you're using Nant, rebuild and run.
• Do a clean checkout, build that from scratch, then copy over all data files (*.db, *.xml, *.ini) from your old installation, rebuild and run.

If all else fails, join #opensim on freenode, or send an email to theopensim-users mailing list.